Census workers who did no work were paid

Thousands of workers hired last year for temporary positions by the U.S. Census Bureau were trained and paid but never worked for the agency, while others who fulfilled assignments overbilled for travel expenses, according to an audit released Tuesday.

A quarterly report by the Commerce Department's inspector general noted that the Census Bureau spent less money than budgeted during the fourth quarter of 2009, but it warned of potential cost overruns as the agency prepares to hire more than 1 million temporary workers this spring -- the largest temporary civilian hiring in government history.

The Census Bureau hired roughly 140,000 temporary workers last spring to prepare for this year's national head count. More than 100,000 "address canvassers" were reimbursed a combined $83 million for driving more than 150 million miles as they verified residential addresses, the audit said. Federal mileage reimbursement rates were set at 58.5 cents per mile in August 2008 but dropped to 55 cents Jan. 1, 2009. Some of the agency's regional offices mistakenly reimbursed 3.9 million miles at the higher rate, costing about $136,000 in overpayments, auditors found.